Buggy code:
private this . insideQualifiedReference = true ; CompletionOnQualifiedNameReference ref = ( ( CompletionOnQualifiedNameReference ) ( astNode ) ) ; this . completionToken = ref . completionIdentifier ; long completionPosition = ref . sourcePositions [ ( ( ref . sourcePositions . length ) - 1 ) ] ; if ( qualifiedBinding instanceof VariableBinding ) { setSourceRange ( ( ( int ) ( completionPosition > > > 32 ) ) , ( ( int ) ( completionPosition ) ) ) ; TypeBinding receiverType = ( ( VariableBinding ) ( qualifiedBinding ) ) . type ; if ( receiverType != null ) { findFieldsAndMethods ( this . completionToken , receiverType , scope , ref , scope , false , false ) ; } } else { if ( qualifiedBinding instanceof ReferenceBinding ) { ReferenceBinding receiverType = ( ( ReferenceBinding ) ( qualifiedBinding ) ) ; setSourceRange ( ( ( int ) ( completionPosition > > > 32 ) ) , ( ( int ) ( completionPosition ) ) ) ; findMemberTypes ( this . completionToken , receiverType , scope , scope . enclosingSourceType ( ) , false , new ObjectVector ( ) ) ; findClassField ( this . completionToken , ( ( TypeBinding ) ( qualifiedBinding ) ) , scope ) ; MethodScope methodScope = null ; if ( ( ( scope instanceof MethodScope ) && ( ! ( ( ( MethodScope ) ( scope ) ) . isStatic ) ) ) || ( ( ( methodScope = scope . enclosingMethodScope ( ) ) != null ) && ( ! ( methodScope . isStatic ) ) ) ) { if ( ( this . completionToken . length ) > 0 ) { findKeywords ( this . completionToken , new char [ ] [ ] { Keywords . THIS } ) ; } else { int relevance = computeBaseRelevance ( ) ; relevance += computeRelevanceForInterestingProposal ( ) ; relevance += computeRelevanceForCaseMatching ( this . completionToken , Keywords . THIS ) ; relevance += computeRelevanceForRestrictions ( IAccessRule . K_ACCESSIBLE ) ; this . noProposal = false ; if ( ! ( this . requestor . isIgnored ( CompletionProposal . KEYWORD ) ) ) { CompletionProposal proposal = this . createProposal ( CompletionProposal . KEYWORD , this . actualCompletionPosition ) ; proposal . setName ( Keywords . THIS ) ; proposal . setCompletion ( Keywords . THIS ) ; proposal . setReplaceRange ( ( ( this . startPosition ) - ( this . offset ) ) , ( ( this . endPosition ) - ( this . offset ) ) ) ; proposal . setRelevance ( relevance ) ; this . requestor . accept ( proposal ) ; if ( CompletionEngine . DEBUG ) { this . printDebug ( proposal ) ; } } } } findFields ( this . completionToken , receiverType , scope , new ObjectVector ( ) , new ObjectVector ( ) , true , ref , scope , false , true ) ; findMethods ( this . completionToken , null , receiverType , scope , new ObjectVector ( ) , true , false , false , ref , scope , false , false , true ) ; } else { if ( qualifiedBinding instanceof PackageBinding ) { setSourceRange ( astNode . sourceStart , ( ( int ) ( completionPosition ) ) ) ; findTypesAndSubpackages ( this . completionToken , ( ( PackageBinding ) ( qualifiedBinding ) ) ) ; } } } } else { if ( astNode instanceof CompletionOnQualifiedTypeReference ) { this . insideQualifiedReference = true ; this . assistNodeIsClass = astNode instanceof CompletionOnQualifiedClassReference ; this . assistNodeIsException = astNode instanceof CompletionOnQualifiedExceptionReference ; this . assistNodeIsInterface = astNode instanceof CompletionOnQualifiedInterfaceReference ; CompletionOnQualifiedTypeReference ref = ( ( CompletionOnQualifiedTypeReference ) ( astNode ) ) ; this . completionToken = ref . completionIdentifier ; long completionPosition = ref . sourcePositions [ ref . tokens . length ] ; if ( qualifiedBinding instanceof ReferenceBinding ) { setSourceRange ( ( ( int ) ( completionPosition > > > 32 ) ) , ( ( int ) ( completionPosition ) ) ) ; findMemberTypes ( this . completionToken , ( ( ReferenceBinding ) ( qualifiedBinding ) ) , scope , scope . enclosingSourceType ( ) , false , new ObjectVector ( ) ) ; } else { if ( qualifiedBinding instanceof PackageBinding ) { setSourceRange ( astNode . sourceStart , ( ( int ) ( completionPosition ) ) ) ; findTypesAndSubpackages ( this . completionToken , ( ( PackageBinding ) ( qualifiedBinding ) ) ) ; } } } else { if ( astNode instanceof CompletionOnMemberAccess ) { this . insideQualifiedReference = true ; CompletionOnMemberAccess access = ( ( CompletionOnMemberAccess ) ( astNode ) ) ; long completionPosition = access . nameSourcePosition ; setSourceRange ( ( ( int ) ( completionPosition > > > 32 ) ) , ( ( int ) ( completionPosition ) ) ) ; this . completionToken = access . token ; findKeywords ( this . completionToken , new char [ ] [ ] { Keywords . NEW } ) ; findFieldsAndMethods ( this . completionToken , ( ( TypeBinding ) ( qualifiedBinding ) ) , scope , access , scope , false , ( ( access . receiver ) instanceof SuperReference ) ) ; } else { if ( astNode instanceof CompletionOnMessageSend ) { setSourceRange ( astNode . sourceStart , astNode . sourceEnd , false ) ; CompletionOnMessageSend messageSend = ( ( CompletionOnMessageSend ) ( astNode ) ) ; TypeBinding [ ] argTypes = computeTypes ( messageSend . arguments , ( ( BlockScope ) ( scope ) ) ) ; this . completionToken = messageSend . selector ; if ( qualifiedBinding == null ) { findImplicitMessageSends ( this . completionToken , argTypes , scope , messageSend , scope ) ; } else { findMethods ( this . completionToken , argTypes , ( ( ReferenceBinding ) ( qualifiedBinding ) ) , scope , new ObjectVector ( ) , false , true , false , messageSend , scope , false , ( ( messageSend . receiver ) instanceof SuperReference ) , true ) ; } } else { if ( astNode instanceof CompletionOnExplicitConstructorCall ) { setSourceRange ( astNode . sourceStart , astNode . sourceEnd , false ) ; CompletionOnExplicitConstructorCall constructorCall = ( ( CompletionOnExplicitConstructorCall ) ( astNode ) ) ; TypeBinding [ ] argTypes = computeTypes ( constructorCall . arguments , ( ( BlockScope ) ( scope ) ) ) ; findConstructors ( ( ( ReferenceBinding ) ( qualifiedBinding ) ) , argTypes , scope , constructorCall , false ) ; } else { if ( astNode instanceof CompletionOnQualifiedAllocationExpression ) { setSourceRange ( astNode . sourceStart , astNode . sourceEnd , false ) ; CompletionOnQualifiedAllocationExpression allocExpression = ( ( CompletionOnQualifiedAllocationExpression ) ( astNode ) ) ; TypeBinding [ ] argTypes = computeTypes ( allocExpression . arguments , ( ( BlockScope ) ( scope ) ) ) ; ReferenceBinding ref = ( ( ReferenceBinding ) ( qualifiedBinding ) ) ; if ( ref . isClass ( ) ) { if ( ! ( ref . isAbstract ( ) ) ) { findConstructors ( ref , argTypes , scope , allocExpression , false ) ; } } <START_BUG> if ( ! ( ref . isFinal ( ) ) ) { <END_BUG>

Fix:
if ( ( ! ( ref . isFinal ( ) ) ) && ( ! ( ref . isEnum ( ) ) ) ) {